Pulser tube



March 15, 1949.

R. C. HILLIARD PULSER TUBE Filed Sept. 15, 1945 INVENTOR. Robert 6.Hiiliumi Patented Mar. 15, 1949 UNITED STATES PATENT OFFICE Robert C.Hilliard, Salem, Mass., assignor to Sylvania Electric Products Inc.,Salem, Mass... a corporation of Massachusetts Application September 15,1945, Serial No. 616,601

.1 p This invention relates to gaseous discharge tubes and particularlyto those of the type in which the source of electrons is a cathode spot.It may be designed, if desired, so that the dissipation of heat at theelectrode makes the tube useful in iving rapid capacitor discharges. Itmay be used as a strobotron and for other purposes, as in combustionengine ignition circuits.

An object of this invention is to provide a cold- I cathode, gaseousdischarge tube which will be a. source of extremely rapid and distinctflashes or pulses.

Another object is to provide an electron discharge tube which functionsat very high voltages.

Another object is to provide a low pressure discharge tube small in sizeand capable of handlinn high average currents.

A further object is to provide a rigid discharge tube which will giverapid and distinct pulses of current when used in connection with avibrating unit, a motor, or the like.

A feature of this invention is the use of a ceramic cup to enclose andinsulate the anode and grid. Another feature is the use of vent holes inone end of said ceramic cup to allow the cathode to dissipate heat withthe sputtered material to the walls of the tube, thereby coolingsufiiciently to be useful in high voltage circuits. Another feature isthe rigid mounting of the electrodes to permit the device to withstanduse in.

a motor or any vibrating unit.

Other objects and features of this invention will be explainedhereinafter, and will be particularly pointed out in the claims.

Figure 1 is a perspective view of the cold-oath ode gaseous dischargetube.

Figure 2 is a longitudinal sectional view of said cold-cathode, gaseousdischarge tube enlarged.

In Figure 1, the anode wire I of tantalum is welded to material suitablefor sealing to glass and is sealed into the glass sleeve 2 whichsupports the carbon grid 3. The cylindrical carbon grid 3 and the anodeI are enclosed in an insulating ceramic cup 4 designed with vent holes 5at the cathode end.

The gas, expanding because of the discharge, can blow out through theholes 5, together with someof the sputtered caesium. This releases thepressure inside the ceramic cup and may reduce 8 Claims. (01. 176-122)2' the amount of sputtered material therein also.

It may also help to dissipate the heat, but the latter effect may alsobe achieved by adding cooling fins to the outside of the cathode cup, ifdesired.

- The open cathode cup 6, with its internal n11- ing it of low workfunction material allows intimate contact with the gas without formationof a glow on the outside. .The lead-in wire I, and the support wire 9are positioned to support and to make compact and rigid the assembledparts of the tube. The glass envelope 8 may be filled with helium at lowpressure to further quicken the response of the device and to increasethe "hold-off factor.

In Figure 2, the tantalum anode is sealed into the glass sleeve andsurrounded by a cylindrical carbon grid; both anode and grid areinsulated and enclosed by a ceramic cup. The wires 1 and 9, one ofwhich, I, is a lead-in wire, support the cup and pass to the cathodewhich is covered with caesium chloride and aluminum, material which onsputtering does not readily cling to other parts ,of the tube. Caesiumgoes off as a gas through 26 the vent holes in the ceramic cup anddissipates the heat.

What -I claim is: I

1. A gaseous discharge tube comprisin a container, a gaseous fillingtherein, an anode therein, a cylindrical carbon electrode around saidanode, a cathode having material of low work function on its irmersurface, an insulating cylinder extending from said cathode andenclosing said carbon electrode, and lead-in means to said cathode, saidanode, and said carbon electrode.

2. The combination of claim 1, in which the insulating cylinder hasholes therein between the cathode and carbon electrode for the diffusingof gas.

3. The combination of claim 1, in which the anode is a tantalum wire.

4. A gaseous discharge tube comprising a sealed container, a filling -ofgas at low pressure but spaced therefrom, a lead-in wire connected to 3said anode. another lead-in wire connected to said cathode, and anotherlead-in wire connected to said carbon electrode.

5. A gaseous discharge tube comprising a sealed container, a filling orgas at low pressure therein, a stem press extending inside saidcontainer, lead-in wires extending into said container from said stempress, a metal cup attached to the end or one or said lead-in wires. alow work function material partly filling said cup, a hollow insulatingcylinder having an external shoulder at its ,end and fitted into saidcup up to said shoulder but not extending into said low work functionmaterial, said cylinder having a series of vent holes therein near saidcup and, I D STA PAT 8 having an internal shoulder at the end Oppositeto that having the external shoulder, a carbon cylinder connected to oneof said lead-in wires other than that connected to said metal cup andhaving an external shoulder at one end and an internal shoulder at theother, said external shoulder fitting into the internal shoulder of theinsulating cylinder, a wire anode connected to one of said lead-in wiresother than those connected to said metal cup and to said carboncylintending out of said glass sleeve, and a lead-in wire contactingsaid. carbon cylinder and extending through the stem press.

6. The combination of claim 5, in which the 5 gas filling is helium.

'1. The combination or claim 1, in which the gas filling is helium.

8. The combination of claim 4, in which the gas filling is helium.

The following references are of record in the ROBERT C. HILIMRD.

REFERENCES CITED file of this patent:

, Number der and extending from the-stem press partway into said carboncylinder but spaced therefrom, a glass sleeve extending upward from thestem and around said wire anode for a short distance and fittingintosaid carbon ring below said internal shoulder, the end of said wireelectrode ex- Number France May 16, 1938

